Electrical terminal connector

ABSTRACT

A terminal member is initially in the form of a screw having a head that is square as viewed along the screw axis, with integral upstanding flanges extending along a pair of its opposite sides. End portions of leads are laid between the flanges. The flanges are sheared in half parallel to the screw axis and simultaneously the rear tabs of the flanges are bent inwardly and down to grip the leads. The extreme front end portions of the leads, between the still upstanding front tabs, are then resistance welded to the head.

O v United States Patent 1 1 11 1 3,739,323 Spors 4 June 12, 1973 ELECTRICAL TERMINAL CONNECTOR 3,127,533 3/1964 Gardner, Jr 310/249 1 Inventor: James 1 West Bend, 323331133 15/1322 52252;:::::::::::::::::::::::: 3133113531 73 ASSignee: Briggs & s u Corporation, 3,566,008 2/1971 Ettlinger et a1 174/94 Wauwatosa, Wis. Primary Examiner-Jordan Franklin [22] Flled' 1972 Assistant Examiner-Peter Nerbun [21] Appl. No.: 247,161 Attorney-Ira Milton Jones [52] US. Cl. 339/275, 174/94, 310/71, [57] ABSTRACT 51 I t iig gg A terminal member is initially in the form of a screw i 276323 having a head that is square as viewed along the screw 3 7 2? D 115 A W axis, with integral upstanding flanges extending along /8 4 9 219/148 a pair of its opposite sides. End portions of leads are laid between the flanges. The flanges are sheared in 56 R f CQt d half parallel to the screw axis and simultaneously the 1 e erences l 6 rear tabs of the flanges are bent inwardly and down' to UNITED STATES PATENTS grip the leads. The extreme front end portions of the 2,109,073 -2/1938 Nieman 24/115 A leads, between the still upstanding front tabs, are then 2,600,012 6/1952 Macy 24/115 A resistance welded to the head. 2,909,758 10/1959 Modrey 174/94 X 3,020,333 2/1962 Bangert et al. 174/94 3 Claims, 5 Drawing Figures Patented June 12, 1973 2 Sheets-Sheet 1 FicJ.

Patented June 12, 1973 This invention relates to electrical terminal connectors, and more particularly to a method and means for providing a good electrical and mechanical connection between wire conductor means and another part of an electrical apparatus.

The general object of this invention is to provide a method and means for affording a sound connection between one or more electrical leads and another conductor, which connection comprises a screw threaded terminal member to which the leads are attached in a manner that firmlysecures both their insulation and their conducting portions to the terminal member.

Another and more specific object of this invention is to provide an electrical terminal member which is in thenature of a bolt or stud and which can thus be installed through a hole in the frame or other structural part of a motor or similar electrical machine, either in insulated relation to the structural part or in grounded relation thereto, to beretained in place by a nut or similar securement means, and which terminal member has provision for effecting a quick, easy and very good securement of leads to it.

It is also a specific object of this invention to provide a terminal member of the character described, having" a screw threaded shank portion and a novel head portion, and a' novel method and means for connecting a lead or leads to the head portion of said terminal member by a combination of crimping and welding operations whereby a connection is obtained between the terminal and the lead or leads that is extremelystrong mechanically and of minimum resistance electrically.

It is also an object of this invention to provide terminal connector means of the character described that is particularly suitable for installation in an electric motorhaving a commutator andbrushes, to provide a terminal to which brush leads are permanently connected at the interior of the motor frame and which is readily accessible at the exterior of the motor for detachable connection of a supply main thereto.

With these observations and objectives in mind, the

manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings, which exemplify the invention, it being understood that changes may be made in the precise method of practicing the invention and in the specific apparatus disclosed herein without departing from the essentials of the invention set forth in the appended claims.

The accompanying drawings illustrate one complete example of an embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. I is a sectional view of an electric motor incorporating an electrical terminal connector that embodies the principles of this invention, the view being thus illustrative of an application of the terminal connector;

FIG. 2 is a perspective view of the terminal member per se;

FIG. 3 is a perspective view illustrating more or less diagrammatically the step of crimping portions of the tabs or flanges on the terminal member over the con- 1 ductor means;

FIG. 4 is' a perspective view illustrating the condition of the terminal member at the conclusion of the operation shown in FIG. 3; and

FIG. 5 is a perspective view illustrating more or less diagrammatically the step of fusing'ly bonding the conductor means. to the terminal member.

Referring now more particularly to the accompanying drawings, the numeral 5 designates generally an electric motor which is illustrative of the type of electrical apparatus wherein the present invention has particular utility. The motor 5 has a generally conventional frame that comprises a substantially cup-shaped end bell 6, and has a rotor comprising a commutator 7 that is engaged by brushes 8. Brush holder means 9 of insulating material support the brushes for limited sliding motion in directions radial to the motor, and springs 10, reacting between the brush holder means and the brushes, maintain the brushes engaged with the commutator. The particular brush holder means here illustrated is that of my copending application, Ser. No. filed to which reference may be made for further de tails.

A brush lead conductor wire 11 is connected to each of the brushes 8 near its radially outer end. Since the brushes tend to move in the brush holder means, and since the brush leads 11 must neither interfere with such brush movement nor be adversely affected by it, the brush leads are of stranded copper. At least the ungrounded leads have insulation sleeves, preferably of woven nylon or similar supple material. Two of the brushes are grounded by reason of the fact that their leads are connected to conventional eyelet terminal connectors 12, which are in turn secured to screws 13 that are threaded into the end bell. As disclosed in the aforesaid copending application, the screws 13 also .serve to secure the brush holder means 9 to the end bell.

The other two brush leads are connected to a terminal member 15 of this invention, to provide for their connection with an ungrounded supply main at the exterior of the motor. y

In general, the terminal member 15 has a screw threaded shank portion 16 that projects through the circumferential wall'of the cup-shaped end bell and has a novel head 17 which is at the inside of the end bell and to which the ungrounded brush leads areconnected at their ends remote from the brushes. The terminal member is held in place by means of a nut 18 on its shank portion. A plastic insulator l9 underlying the head portion of the terminal member, and anotherplas tic insulator 20surroundihgitsshank portion and underlying the nut 18, cooperate to insulate the tenninal member from the end bell. v

The head portion of the terminal member, asbest seen in FIG. 2, is square in planform as viewed along the axis of the' shank portion. Considering the terminal member with its head uppermost, and in the form that it has before securement of conductor means to it,'its head has a substantially flat top surface 22 and has a pair of rectangular tabs or flanges 23 that project upwardly from that surface along opposite side edges of the head. The terminal member'can be initially made as a square headed screw, and then a wide slot can be milled across its head to define the tabs or flanges 23.

Preferably each flange is spaced inwardly a smalldisside thereof, so that when the flange is subsequently bent inwardly, it is encouraged to take a curling bend around a wire beneath it rather than sharply creasing and possibly cracking at its junction with the surface 22.

To establish a connection between the terminal member and the conductor means to be secured to it, the terminal member is placed in a suitable fixture 26 that holds it upright with its head portion uppermost. The end portions of the conductor means that are to be secured to the terminal member are then laid on its top surface 22, between its upstanding flanges. This end portion of the wire or wires should extend substantially the full length of the flanges, with the main body of the conductor means extending rearwardly from the terminal member. If it is desired to secure the insulation on the conductor means to the terminal member, only about the front half of the conductor means end portion that overlies the terminal member head will be bared.

A forming tool now shears the flanges vertically down their middles, to divide each flange into front and rear tab portions 29 and 30, and simultaneously bends the rear tab portions inwardly toward one another and tightly down over the conductor means. The equipment for effecting this shearing and crimping operation can comprise a tool having three parts, one of them being a finger 31 that is received between the front portions 29 of the flanges with a close fit and the other two parts 32 being movable inwardly from opposite sides of the flanges and engaging only the rear portions 30 of the flanges for shearing cooperation with the finger 31.

The shearing and crimping operation is followed by a welding operation, which is illustrated in FIG. 5. The jig or holder in which the terminal member is secured is connected with one side of a welding circuit, and a probe 34 connected with the other side of that circuit is inserted between the upstanding front tab portions 29 and down onto the bare end portion of the conductor means. As a result, a resistance welding takes place by which the end portion of the conductor means is fusingly bonded to the terminal member.

From the foregoing description taken with the accompanying drawings it will be apparent that this invention provides a method and means for effecting a good electrical and mechanical connection between a conductor wire or conductor wires and another part of an electrical apparatus, which connection comprises a terminal member that can be connected and secured to said other part in the manner of a bolt.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims:

1. An electrical terminal assembly comprising wire conductor means and means for electrically and mechanically connecting the conductor means with another part, said assembly being characterized by:

A. the means for connecting the conductor means with another part comprising a terminal member having 1. a screw-threaded shank portion,

2. a head having a top surface which is substantially normal to the axis of the shank portion, and 3. integral elongated tabs on the head that join said top surface of the head along parallel lines at opposite sides of the head, each of said tabs having a. a rear portion bent inwardly over said top surface toward the rear portion of the other tab, and

b. an upstanding front portion which is substantially normal to said surface and which opposes the front portion of the other tab; said head, tabs, rear and upstanding front portion being fabricated from a single piece of material and B. the conductor means having an end portion received between the upstanding front portions of said tabs and fusingly bonded to said surface of the head, and having a portion adjacent to its said end portion that is clampingly confined between said surface and the rear portions of said tabs.

2. The method of providing for the electrical and mechanical connection of wire conductor means with another part of an electrical apparatus which comprises:

A. forming a single piece terminal member having 1. a screw threaded shank,

2. an enlarged head at the top of said shank with a substantially flat upper surface, and

3. a pair of fin-like tabs that project upwardly from said surface and extend fore-and-aft along opposite edges thereof, substantially parallel to one another;

B. placing an end portion of the conductor means upon said surface and between the tabs, with the main portion of the conductor means extending rearwardly from the terminal member;

C. bending the rear portion of each tab downwardly and inwardly over the conductor means to clampingly confine the conductor means against said surface; and

D. fusingly bonding to said surface the end portion of the conductor means that lies between the front portions of said tabs.

3. An electrical terminal assembly comprising wire conductor leads and means for electrically and mechanically connecting the conductor leads with another part, said assembly being characterized by:

A. the means for connecting the conductor leads comprising a terminal member having 1. an elongated cylindrical shank portion,

2. a head having a top surface which is overlain by the conductor leads,

3. integral rear tab portions on the head, bent inwardly and down from near opposite side edges of the head and tightly overlying the conductor leads, near ends thereof, to grippingly confine the leads against said surface, and

4. integral front tab portions on the head, projecting up from said surface near said side edges of the head and between which said ends of the conductor leads are disposed; and

B. said ends of the conductor leads being fusingly bonded to said surface of the head. 

1. An electrical terminal assembly comprising wire conductor means and means for electrically and mechanically connecting the conductor means with another part, said assembly being characterized by: A. the means for connecting the conductor means with another part comprising a terminal member having
 1. a screw-threaded shank portion,
 2. a head having a top surface which is substantially normal to the axis of the shank portion, and
 3. integral elongated tabs on the head that join said top surface of the head along parallel lines at opposite sides of the head, each of said tabs having a. a rear portion bent inwardly over said top surface toward the rear portion of the other tab, and b. an upstanding front portion which is substantially normal to said surface and which opposes the front portion of the other tab; said head, tabs, rear and upstanding front portion being fabricated from a single piece of material and B. the conductor means having an end portion received between the upstanding front portions of said tabs and fusingly bonded to said surface of the head, and having a portion adjacent to its said end portion that is clampingly confined between said surface and the rear portions of said tabs.
 2. a head having a top surface which is substantially normal to the axis of the shank portion, and
 2. an enlarged head at the top of said shank with a substantially flat upper surface, and
 2. The method of providing for the electrical and mechanical connection of wire conductor means with another part of an eleCtrical apparatus which comprises: A. forming a single piece terminal member having
 2. a head having a top surface which is overlain by the conductor leads,
 3. An electrical terminal assembly comprising wire conductor leads and means for electrically and mechanically connecting the conductor leads with another part, said assembly being characterized by: A. the means for connecting the conductor leads comprising a terminal member having
 3. a pair of fin-like tabs that project upwardly from said surface and extend fore-and-aft along opposite edges thereof, substantially parallel to one another; B. placing an end portion of the conductor means upon said surface and between the tabs, with the main portion of the conductor means extending rearwardly from the terminal member; C. bending the rear portion of each tab downwardly and inwardly over the conductor means to clampingly confine the conductor means against said surface; and D. fusingly bonding to said surface the end portion of the conductor means that lies between the front portions of said tabs.
 3. integral rear tab portions on the head, bent inwardly and down from near opposite side edges of the head and tightly overlying the conductor leads, near ends thereof, to grippingly confine the leads against said surface, and
 3. integral elongated tabs on the head that join said top surface of the head along parallel lines at opposite sides of the head, each of said tabs having a. a rear portion bent inwardly over said top surface toward the rear portion of the other tab, and b. an upstanding front portion which is substantially normal to said surface and which opposes the front portion of the other tab; said head, tabs, rear and upstanding front portion being fabricated from a single piece of material and B. the conductor means having an end portion received between the upstanding front portions of said tabs and fusingly bonded to said surface of the head, and having a portion adjacent to its said end portion that is clampingly confined between said surface and the rear portions of said tabs.
 4. integral front tab portions on the head, projecting up from said surface near said side edges of the head and between which said ends of the conductor leads are disposed; and B. said ends of the conductor leads being fusingly bonded to said surface of the head. 